Perissomyrmex fissus

Perissomyrmex fissus

Perissomyrmex fissus is a tiny myrmicine ant from the Crematogastrini tribe, newly described from Yunnan Province, China in 2004. Workers measure just 3.1mm in total length, making them one of the smaller ant species in the hobby. They have a distinctive appearance with a nearly square head,9-segmented antennae (unusual for Myrmicinae), strong propodeal spines, and a striking black gaster contrasting with a brown head and alitrunk. The species was discovered at 2500m elevation in the Ailao Mountain Nature Reserve, living in a primary sub-alpine moist evergreen broadleaf forest. This is only the third known species in the genus Perissomyrmex, making it a rare and unusual addition to antkeeping.

Quick Summary

• Difficulty: Expert
• Origin & Habitat: Yunnan Province, China at 2500m elevation in primary sub-alpine moist evergreen broadleaf forest ^[1]. The high-altitude location suggests a cool, damp mountain habitat.
• Colony Type: Colony structure is completely unknown, this species was described from a single worker specimen in 2004 and has no published biological studies.
• Size & Growth:
  • Queen: Unknown, only worker caste has been described ^[1]
  • Worker: 3.1mm total length (TL 3.1mm, HL 0.83mm, HW 0.80mm) ^[1]
  • Colony: Unknown, only one specimen has ever been collected
  • Growth: Unknown
  • Development: Unknown, no development data exists for this species (Development timeline cannot be estimated due to complete lack of biological data. Related Perissomyrmex species have not been studied.)
• Antkeeping:
  • Temperature: Inferred from high-altitude habitat to prefer cool conditions, roughly 15-22°C. Start at room temperature (around 20°C) and observe colony activity. Avoid overheating.
  • Humidity: Inferred from 'moist evergreen broadleaf forest' habitat, requires high humidity, likely 70-85%. Keep substrate consistently damp but not waterlogged.
  • Diapause: Unknown, likely required given temperate mountain location at 2500m, but no direct studies exist.
  • Nesting: Ground-nesting species collected from soil sample. In captivity, a test tube setup with moist substrate or a small acrylic/plaster nest with high humidity would be appropriate. Their tiny size means chambers should be small and tight.
• Behavior: Behavior is completely unstudied. Based on their small size and mountain habitat, they are likely docile and may be shy foragers. Their tiny 3.1mm size means escape prevention is critical, they can squeeze through standard mesh. Use fine mesh or fluon barriers. No information on sting potency exists, but given their size, any sting would be negligible.
• Common Issues: complete lack of biological data makes captive care extremely challenging, only known from a single specimen, no captive colonies exist in the hobby, hibernation requirements are unknown but likely needed given altitude, tiny size creates significant escape risk through standard barriers, no information on diet acceptance, feeding strategy is entirely speculative

Discovery and Rarity

Perissomyrmex fissus represents one of the rarest ants in the world to keep, having been described only in 2004 from a single worker specimen collected in China's Yunnan Province. The genus Perissomyrmex contains only four known species worldwide, making it one of the least studied ant groups in existence. This species was found at 2500m elevation in the Ailao Mountain Nature Reserve, in a primary sub-alpine moist evergreen broadleaf forest, a cool, damp mountain environment. No biological studies have ever been published on this species, meaning everything about their colony structure, diet, development, and behavior remains completely unknown. This is not a species for beginners or even intermediate antkeepers, it represents a genuine frontier in antkeeping where keepers may need to pioneer entirely new care approaches. ^[1]

Housing and Escape Prevention

Given their tiny 3.1mm worker size, Perissomyrmex fissus presents extreme escape prevention challenges. Standard ant keeping mesh will not contain them, you must use fine mesh (at least 0.5mm or smaller) or apply fluon barriers to all enclosure edges. A test tube setup with a small water reservoir works well for founding colonies, as this mimics their natural ground-nesting behavior. The test tube should be kept in a dark location to reduce stress, as these are likely subterranean or cryptic foragers. For established colonies, a small acrylic nest with tight chambers scaled to their tiny size would be appropriate. The nest should maintain consistently high humidity to match their moist forest habitat. ^[1]

Temperature and Humidity Management

The high-altitude origin of this species (2500m in Yunnan) strongly suggests they prefer cool, stable conditions. Avoid any heating elements unless the colony shows clear signs of being too cold (inactivity, failure to forage). Target room temperature around 18-22°C as a starting point, then adjust based on colony behavior. Humidity should be kept high, think damp forest floor rather than dry conditions. The substrate should feel consistently moist but never waterlogged. Provide a gradient by placing the water reservoir at one end of the test tube so ants can choose their preferred moisture level. Given the complete lack of data, these are educated guesses based on habitat rather than proven requirements. ^[1]

Feeding Strategy

No published information exists on what Perissomyrmex fissus eats in the wild or in captivity. Their small size and membership in the Myrmicinae suggests they likely forage for tiny prey items and may tend aphids for honeydew, but this is entirely speculative. For a newly acquired colony, start with the safest options: tiny live prey like springtails or fruit flies, and a sugar source like honey or sugar water offered on a cotton wick. Observe carefully for any acceptance. Given their mountain forest origin, they may be predaceous on small invertebrates. Do not overfeed, remove any uneaten prey after 24-48 hours to prevent mold. This species should be considered experimental in terms of diet, and keepers may need to discover their preferences through careful trial and error.

Legal and Ethical Considerations

Perissomyrmex fissus has never been exported from China for the antkeeping hobby, and no captive breeding populations exist anywhere in the world. Any specimens would need to be collected from the wild in Yunnan Province, which raises significant concerns. The species was described from a single specimen collected in 2003,suggesting wild populations are extremely small or localized. Collecting from the type locality could potentially harm or even eliminate the only known population. Additionally, China's export regulations on native insects are strict, and permits for scientific collection are typically required. This species should be considered a candidate for conservation rather than collection, there are likely fewer than a dozen known specimens of this ant in existence. ^[1]

Frequently Asked Questions

References